1. Field of the Invention
The present invention relates to garage door openers and in particular to a novel garage door opener which can be shipped in units and easily and simply assembled and installed.
2. Description of the Prior Art
The present garage door openers are sold as units which are to be connected to garage or other doors which are separately manufactured and installed. Such garage doors are very heavy which makes them difficult to open and are very expensive. Certain of the doors are too light and have poor insulation and security. The garage doors are mounted with steel hardware on rails and are difficult to assemble and are noisy to install. The garage doors require substantial space in the ceiling above the door when in the opened position.
Present day garage doors and openers require frequent maintenance, painting, spring adjustment and lubrication. Also, the present garage door openers are unsafe as, for example, when a spring fails which causes the door to fall and also the emergency release may be inaccessible which could result in injury to personnel. Present day garage door openers are normally installed after the door has been installed and, thus, a two step installation is required where first the garage door is mounted and then subsequently the garage door opener is connected to the garage door to actuate it. Such installations require additional wiring of the receiver and switches and each installation is different and, thus, the obstruction reversing forces, the limit switches at the top and bottom and the other parameters for the door and the opener are different for each installation.
This results in dangerous situations in that the installation may be improperly connected and also the various adJustments may be improperly made resulting in injury and even death to personnel. For example, in garage door openers of the prior art, since each door has different weight and requires different pull-down and pull-up force it is necessary to have a motor which is larger than would be required for other doors and garage door openers. This leads to excessive speeds and forces which can be applied to the garage door which can result in injury. Also, since the weight of each door varies, the obstruction detecting force is made adJustable by either the installer or the home owner and if such adjustment is made to be too tight, the door may not reverse if it encounters a child, for example, and this has resulted in the death of children.